TBW stands for terabytes written. It specifies how much data a solid-state drive (SSD) can accept during write operations over its lifetime before the storage cells degrade beyond reliable use.
SSDs use flash memory cells that have a finite number of write cycles. Each time you save a file, modify a document, or install software, you trigger write operations. After millions of these cycles, the cells wear out. Manufacturers test drives to determine when this happens and publish a TBW rating to tell you roughly when failure becomes likely.
A typical consumer SSD might offer 100 to 600 TBW, depending on capacity and quality. A 1TB drive with a 300 TBW rating means you could theoretically write 300 terabytes of data to it. In practice, most users write far less than this limit. Averaging 50GB of writes per day, you'd reach 300 TBW in roughly 16 years.
TBW ratings usually correlate with warranty length. An SSD rated for 600 TBW typically comes with a 5-year warranty, whilst a 100 TBW drive might have 3 years. Premium or enterprise-grade drives can exceed 1000 TBW.
When buying an SSD, check the TBW figure if you plan heavy use: video editing, gaming with large file transfers, or running a server all demand high write volumes. For everyday tasks like browsing, email, and document editing, even modest TBW ratings provide ample headroom. The rating acts as a durability insurance measure, reassuring you that your drive will stay reliable for years of real-world use.